Socket编程时recv函数错误：Transport endpoint is not connected的解决

Posted 2020-07-24 wwha

今天在做socket网络通信实验时，server端执行到recv函数处报错：Transport endpoint is not connected。

以下是server和client的源码：

server.c

 1 #include <stdio.h>
 2 #include <arpa/inet.h>
 3 #include <sys/socket.h>
 4 #include <string.h>
 5 #include <unistd.h>
 6 #include <stdlib.h>
 7 #define SERVER_PORT 5000
 8 
 9 
10 int main(){
11     /*地址初始化*/
12     struct sockaddr_in serveraddr;
13     struct sockaddr_in clientaddr; 
14      memset(&serveraddr,0,sizeof(serveraddr)); 
15      serveraddr.sin_family = AF_INET; 
16      serveraddr.sin_addr.s_addr = INADDR_ANY;
17      serveraddr.sin_port = htons(SERVER_PORT);
18     bzero(&(serveraddr.sin_zero),8);
19     //1.create sock
20     int sock,conn,sbind,lis;
21     char buf[32];
22     sock = socket(AF_INET,SOCK_STREAM,0);
23     if(sock ==-1){perror("sock error");exit(1);}
24     //2.bind
25     sbind = bind(sock, (struct sockaddr*)&serveraddr, sizeof(serveraddr));
26      if(sock ==-1){perror("bind error");exit(1);}
27     //3.listen
28     lis = listen(sock, 2);
29     if(lis ==-1){perror("listen error");exit(1);}
30     //4.accept
31     int acc,snd,rec;
32     int len = sizeof(struct sockaddr_in);
33     while(1){
34         acc = accept(sock,(struct sockaddr*)&clientaddr, (socklen_t*)&len);
35         if(acc == -1){
36             perror("accept error!");continue;        
37         }
38         if((rec=recv(sock,buf,1024,0))==-1){perror("server connect failed!");exit(1);}//错误的地方
39         buf[rec]=‘\0‘;
40         if(strcmp(buf,"liu")==0){
41             snd =  send(acc, "Hello，You are connected\n", 24, 0);
42         }
43     }
44 
45     close(sock);
46     return 0;
47 }

client.c

#include <stdio.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#define SERVER_PORT 5000

int main(){
	/*地址初始化*/
	struct sockaddr_in serveraddr; 
	 memset(&serveraddr,0,sizeof(serveraddr)); 
	 serveraddr.sin_family = AF_INET; 
	 serveraddr.sin_addr.s_addr = INADDR_ANY; 
	 serveraddr.sin_port = htons(SERVER_PORT);
	bzero(&(serveraddr.sin_zero),8);
	//1.create sock
	int sock,conn;
	char buf[32];
	sock = socket(AF_INET,SOCK_STREAM,0);
	conn =  connect(sock,  (struct sockaddr*)&serveraddr, sizeof(serveraddr));
	if(conn ==-1){perror("connect error");exit(1);}
	int snd;
	snd =  send(sock, "liu", 4, 0);
	if(snd ==-1){perror("send error");exit(1);}
	int rec;
	if((rec=recv(sock,buf,1024,0))==-1){perror("client connect failed!");exit(1);}
	buf[rec]= ‘\0‘;
	printf("received:%s",buf);
	close(sock);
	return 0;
}

　　错误出在recv这个函数。

首先我们来看看accept函数：int accept(int sockfd, void *addr, int *addrlen); 

它的返回值是一个客户端的套接字描述符，所以recv和send函数的第一个参数应该填写accept返回的套接字描述符。

所以将server.c中的

 if((rec=recv(sock,buf,1024,0))==-1){perror("server connect failed!");exit(1);}
改为：

 if((rec=recv(acc,buf,1024,0))==-1){perror("server connect failed!");exit(1);}即可